Rainforest Eco-systems ( Part of my Dissertation Literture Review, 2009.

 Rainforest Eco-systems and their importance

  Tropical rainforests are thought to contain over half of the worlds plant and animal species (Cotgreave et al 2002), and have the “greatest richness and diversity of species” (Adam 1998) of all terrestrial biomes.

   Over 900 bird species, 33% of the threatened lowland mammal species and 22% of highland mammal species are all from tropical biomes (Dudley et al 2007).  A significant percentage of the worlds threatened species are from tropical forest regions (Dudley et al 2007).

The importance of forests and its relationship with soil and water processes have been known for hundreds of years (Dudley et al 2007). Soil erosion and flooding instigated attempts at reforestation in the Alps and within Scandinavia in the 19^th century (Dudley et al).

 Dudley et al (2007) report the importance of forests on ecological support systems, and their direct effect on human populations both on a global and localised scale, examples being hydrological, soil and fire ecology. Forests are key regulators of water flow, soil conservation and water quality (Dudley et al 2007).

 Dudley et al (2007) report that a third of the 100 largest cities in the world rely on protected forests for a significant proportion of their drinking water. Deforestation and land conversion can lead to increased water table height due to a shortening of plant root systems, bringing soil salts to the surface and leading to potential vegetation degradation (Dudley et al). Forests also have important roles as buffer zones between land types (Dudley et al). Dudley et al (2007) also report on the loss of fish populations due to the removal of mangrove as mangrove roots provide nutrients and breeding areas.

 Continued forest loss has grave ramifications for a sizeable proportion of the planets population. Indonesia alone has a population of over 230 million (CIA World Factbook2008). Land conversion and deforestation impact directly on indigenous peoples and land tenure problems are a frequent issue within developing nations (Dorner and Thiesenhusen 1992).

Research by Takata et al (2009) implies that land clearance may have a profound effect on global and micro level climate.  Their findings suggest that the conversion of land to agriculture within India and China during the 18th and 19^th Century led to a decrease in monsoon rainfall.  Work by Sheil and Murdiyarso (2009) pushes the role of rain forests further by suggesting that the creation of large scale water vapour flow results in extensive rainfall in inland continental regions. They go on to suggest that without the presence of rainforests between the coast lines and the centre of continental bodies, rainfall would drop sharply in in-land areas causing arid conditions (Sheil and Murdiyarso 2009).

The present research into the impact of rainforests into weather systems and rainfall has huge implications considering the present deforestation rates within all tropical regions. Indeed the literature suggests that large scale forests have global implications for weather systems, forests influencing global climate through a number of physical and chemical processes (Bonan 2008). Bonan (2008) stated that bio-geophysical interactions and feedbacks can both increase and decrease climate change feedbacks.  Forests regulate temperature extremes and buffer against adverse weather, and are key in transpiration cycles (Dudley et al 2007). The earth’s forests - and none more than tropical ones - have a huge influence on both micro and global climatic systems with an extensive role in hydrological and nutrient cycles (Kahn and McDonald 1995).

The conservation of remaining rainforest stocks has a major role to play in climate change mitigation. It is estimated that conversion of rainforests releases up to 20% of the worlds carbon dioxide emissions (Brown 1998).  Brown (1998) adds that habitat degradation reduces the resilience of species and their ecosystems to the effects of global climate change. 

Recent literature from Jaenicke et al (2008) and Uryu et al (2008) emphasises the role of peat swamp forests in climate change. Peat forests have vast stores of carbon produced by semi- decomposed vegetative materials (Jaenicke et al 2008). WI (2007) reported that as much as 2.5 Giga-tonnes of carbon were released by forest fires within Indonesia in 1997. Forest conversion accounts for 20-25% of the world’s yearly green house gas emissions (FAO 2005). WI (2006) estimated that Indonesian peat land fires and conversion account for 7% of global GHG emissions. Brown (1998) relates to the importance of soil as a carbon sink and estimates that 75% of terrestrial carbon is stored within soils and peat lands. 

The degradation and loss of the world’s forests also have economical and social ramifications. High biodiversity provides extensive resources and material, financial and spiritual human benefits (Dudley et al 2007).

The forests have huge economic and resource potential, including timber, fruit, rubber, food, fuel, latex, oils, fish stocks, game, resins, building materials, gums, rattan, aromatics, ornamental plants, local plant remedies and medicine (Dudley2007), (Ruiz Perez and Arnold 1996), (Godoy et al 2002). Half of the world’s population use wood as a primary energy source, (Dudley et al) and the number of people dependent on wood fuel is set to grow (FAO 2007).

FAO (2005) estimate that in 2005 wood extraction generated US$64 billion in world revenue and NTFP worth US$4.7 billion. 1.6 Billion people are dependent on forest ecosystems either for fuel, food or medicine and it is estimated that 60 million indigenous people are completely dependent on their forests (FAO 2008). However the small scale use of forests by local populations is often under-estimated in importance (Godoy et al 2002).

 NTFPs are also hugely important within developed nations, with as much as 100 million litres of berries and 20 million litres of mushrooms being collected each year in Sweden (FAO 1986). However NTFP’s are predominantly utilised by low socio-economic classes (Dudley et al 2007). Within the 1980’s the export value of NTFP’s within Indonesia totalled US$238million, however this figure discounts the subsistence importance of NTFPs (Dudley et al 2007).

Godoy et al (2002) suggest that to encourage forest conservation, local populations should benefit more from the use of forests rather than its clearing. Indeed Coomes and Burt (2001) report that traditional local populations extensively utilise NTFPs.  Forests provide work for millions of people globally, both directly within the forests and in secondary support and service industries (Dudley et al). Dudley et al (2007) estimate that paid employment and subsistence equates to 60 million work-years globally, mainly within poor developing nations. The recreational and spiritual use of forests is also commonly underestimated. 50 million day visits per year to State Forestry Commission parks in the United Kingdom in the 1990’s (Dudley et al) highlight the importance of forest habitats to humans.